在调用savechanges之前添加几个相关实体

Question

如果您一次添加多个相关实体，您应该在每次之后调用SaveChanges，还是可以执行一次？我收到一个错误，例如“违反PRIMARY KEY约束”。

订单具有实体记录的导航属性。 我想将记录添加到订单，然后调用savechanges。 当我这样做时，我收到错误抱怨记录上的主键。

我想做这样的事情

Order o = new Order{.......}
Record r1 = new Record{...}
Record r2 = new Record{....}
o.Records.Add(r1)
o.Records.Add(r2)
Context.Orders.Add(o);
Context.SaveChanges()

这不是正确的方法吗？

...

        //populate order entity
        Order o = new Order { AccountKey = iAccnt, OfficeKey = iOffice, UserKey = iUser, CreatedDate = dtCreateDate };

        //save            
        ctx.Orders.Add(o);

        //locations
        Location origin = new Location
        {
            Order = o,
            LocationTypeKey = ctx.LocationTypes.Where(a => a.TypeName == "Origin").First().LocationTypeId,               
            Address1 = " test address 1",
            Address2 = " test Address 2",
            City = oi.OriginCity,
            StateKey = ctx.States.Where(a => a.StateName == oi.OriginState).First().StateId,
            CountryKey = ctx.Countries.Where(a => a.CountryName == oi.OriginCountry).First().CountryId
        };

        Location destn = new Location
        {
            Order = o,
            LocationTypeKey = ctx.LocationTypes.Where(a => a.TypeName == "Destination").First().LocationTypeId,
            Address1 = " test address 1",
            Address2 = " test Address 2",
            City = oi.OriginCity,
            StateKey = ctx.States.Where(a => a.StateName == oi.DestinationState).First().StateId,
            CountryKey = ctx.Countries.Where(a => a.CountryName == oi.DestinationCountry).First().CountryId
        };





        try
        {
            int rows = ctx.SaveChanges();
            if (rows == 0)
            {
                retval = false;
            }
        }
        catch (DbEntityValidationException  ex)
        {
            string exst = ex.ToString();
        }